TY - JOUR
T1 - Tapping mode atomic force microscopy of the hyaluronan derivative, hylan A
AU - Cowman, M. K.
AU - Li, M.
AU - Dyal, A.
AU - Balazs, E. A.
N1 - Funding Information:
The authors thank Dr Jianshe Liu, Polytechnic University, for analysis of hylan A molecular weight. This research was supported by Biomatrix, Inc.
PY - 2000/3
Y1 - 2000/3
N2 - Hylan A, a water-soluble hyaluronan derivative with enhanced molecular weight attributed to protein-mediated crosslinks, has been examined by tapping mode atomic force microscopy (TMAFM). Hylan A was deposited on mica from dilute aqueous solution and imaged in air through a thin layer of adsorbed water. Isolated chains, drawn into extended forms to varying degrees by the movement of a droplet interface across the surface ('molecular combing'), were observed. The majority of the extended chains could be characterized as long linear single-stranded molecules, as is observed for hyaluronan. In a smaller number of observations on extended hylan A, it was possible to observe apparent connections between two chains, presumably mediated by covalent linkage via protein. Hylan A was also commonly observed in less extended forms. Isolated chains of this type often exhibited intramolecular association, the simplest form of which was antiparallel double-stranded (probably double-helical) junction zones. More extensive intramolecular association, via intermittent double- or multi-stranded connections, led to a fenestrated appearance. Intermolecular association was also observed, leading to the formation of network-like matrices. The variety and types of structures observed for hylan A by TMAFM were in excellent agreement with predictions based on physicochemical studies of both hylan A and hyaluronan.
AB - Hylan A, a water-soluble hyaluronan derivative with enhanced molecular weight attributed to protein-mediated crosslinks, has been examined by tapping mode atomic force microscopy (TMAFM). Hylan A was deposited on mica from dilute aqueous solution and imaged in air through a thin layer of adsorbed water. Isolated chains, drawn into extended forms to varying degrees by the movement of a droplet interface across the surface ('molecular combing'), were observed. The majority of the extended chains could be characterized as long linear single-stranded molecules, as is observed for hyaluronan. In a smaller number of observations on extended hylan A, it was possible to observe apparent connections between two chains, presumably mediated by covalent linkage via protein. Hylan A was also commonly observed in less extended forms. Isolated chains of this type often exhibited intramolecular association, the simplest form of which was antiparallel double-stranded (probably double-helical) junction zones. More extensive intramolecular association, via intermittent double- or multi-stranded connections, led to a fenestrated appearance. Intermolecular association was also observed, leading to the formation of network-like matrices. The variety and types of structures observed for hylan A by TMAFM were in excellent agreement with predictions based on physicochemical studies of both hylan A and hyaluronan.
UR - http://www.scopus.com/inward/record.url?scp=0033892348&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0033892348&partnerID=8YFLogxK
U2 - 10.1016/S0144-8617(99)00141-1
DO - 10.1016/S0144-8617(99)00141-1
M3 - Article
AN - SCOPUS:0033892348
SN - 0144-8617
VL - 41
SP - 229
EP - 235
JO - Carbohydrate Polymers
JF - Carbohydrate Polymers
IS - 3
ER -